Compton Gamma-Ray Observatory (CGRO)

The Compton Gamma-Ray Observatory was launched on
April 5, 1991. The second of NASA's great observatories, CGRO has four
instruments that cover an unprecedented six orders of magnitude
in energy, from 30 keV to 30 GeV. Over this energy range CGRO has an
improved sensitivity over previous missions of a full order of
magnitude. It operated for almost 9 years and the mission ended
on June 4 2000. Unlikely most satellites, CGRO was too large to
burn up entirely in the atmosphere during re-entry.
To ensure safety on the Earth's surface, NASA redirected the
spacecraft into Earth's atmosphere with a controlled re-entry.